Slowing to Mars Speed
Written by Nancy Atkinson
When the Mars Science Laboratory (MSL) goes streaking through the Martian atmosphere at more than twice the speed of sound, it’s going to need one of the largest parachutes ever used in a space mission to successfully land a car-sized rover on the Red Planet. The parachute, built by Pioneer Aerospace, has 80 suspension lines, measures more than 50 meters (165 feet) in length, and opens to a diameter of nearly 17 meters (55 feet). It is the largest so called “disk-gap-band†parachute (more on that in a minute) ever built. To get ready for the scheduled 2009 launch of MSL, engineers have begun testing different parts of the parachute in preparation for the ultimate test of the entire parachute system.
Recent successful trials of two parachute packing techniques were performed in the world's largest wind tunnel at NASA's Ames Research Center. Engineers loaded chutes into a cannon and fired them out at 85 mph to simulate events during the real landing, looking for damage to line attachments and other parts. All four tests were successful, and high-speed video data is now being analyzed to select a final parachute design for the mission. But the large parachute is just the beginning of the unique landing technique MSL will use.
MSL will be the first planetary mission to use precision landing techniques, using a rocket-guided entry with a heat shield to steer itself toward the Martian surface similar to the way the space shuttle controls its entry through the Earth's upper atmosphere. In this way, the spacecraft will fly to a desired location above the surface of Mars before deploying its parachute for the final landing. MSL will use a scaled-up version of parachutes used for the Viking and Mars Exploration Rovers mission. Called a Disk-Gap-Band parachute, the name describes the construction of the parachute: a disk forms the canopy, then a small gap, followed by a cylindrical band.
The parachute is deployed using a mortar that is triggered when the vehicle reaches a fixed planet-relative velocity. The parachute is designed to survive loads in excess of 36,000 kilograms (80,000 pounds).
Twice as long and three times as heavy as the Mars Exploration Rovers, MSL is too massive to use airbags like MER. MSL’s large parachute will only be deployed 3 minutes before touchdown which should slow the incoming vehicle enough for retro rockets to fire for the final 500 meters (1,640 feet) of the descent. But after that is where it gets interesting: In the final seconds, the hovering upper stage would act as a crane, lowering the upright rover on a tether to the surface. This is first the “Sky Crane†system will be used in a space mission.
MSL, a roving analytical laboratory, will collect Martian soil and rock samples and analyze them for organic compounds and environmental conditions that could have supported microbial life now or in the past.
Original News Source: JPL Press Release
Filed under: Mars
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April 7th, 2008 at 4:11 pm
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April 8th, 2008 at 4:53 am
Mmm Risky business…
I hope all goes well though.
"MSL, a roving analytical laboratory, will collect Martian soil and rock samples and analyze them for organic compounds and environmental conditions that could have supported microbial life now or in the past."
They've been saying that for 30 years concerning all surface probes…
Does anyone know what are the specifics of this mission compared to the previous rovers?
April 8th, 2008 at 9:28 am
there sending a big bot to dig in dirt again, not going to get much more then that. When they do find something they will call it a mission goal and call it a succesful mission. personaly i don't care if they find anything or not, the real age of Mars discovery begens with a human footprint.
April 8th, 2008 at 5:30 pm
sOI Says:
April 8th, 2008 at 4:53 am
"They've been saying that for 30 years concerning all surface probes…
Does anyone know what are the specifics of this mission compared to the previous rovers?"
The mission is all about more quality and quantity of scientific data. It will be able to travel much farther and faster than current rovers, collect a lot more data and a lot more diverse data etc. Using an analogy to get a fell for the increase in capability – if Sojourner could be compared to the 41 inch Yerkes Refractor, the current rovers would be like the 200 inch Hale reflector and the MSL would be the ESO Very Large Telescope.
Here is a brief rundown of the broad goals:
http://mars.jpl.nasa.gov/msl/science/objectives.html
…and here is a description of the advanced instrumentation of the rover:
http://mars.jpl.nasa.gov/msl/technology/si_is_instrumentation.html
Basically the capabilities of this vehicle will dwarf those of the past and current mars rovers in every way.
Kevin Says:
April 8th, 2008 at 9:28 am
"personaly i don't care if they find anything or not, the real age of Mars discovery begens with a human footprint."
I guarantee you that, even when humans eventually do go to Mars, it'll still be the bots that are contributing 95% of the scientific discoveries. Human space exploration may have been cutting edge in the 60's, but by the time we go to Mars there won't be be much, if anything, left that a human could do more efficiently or better than a robot.
That's not to say that it is not worthwhile to send Humans to Mars, just that it is worthwhile for reasons other than pure scientific discovery…
April 9th, 2008 at 5:12 am
"Human space exploration may have been cutting edge in the 60's, but by the time we go to Mars there won't be be much, if anything, left that a human could do more efficiently or better than a robot."
A robot may be able to work 24/7 but it can't look at a rock and go "hey that looks odd, lets get a closer look" Mans greatest gift is the ability to reason from the abstract and see what is there beyond the obvious. no robot no matter how well it is programed will be able to do that in our lifetime. maybe in 80-100 years but even then a human will always be the better observer.
April 9th, 2008 at 7:43 am
*Sigh* Why can't our satellites be like human devices back here on earth? I mean, a satellite with a sophisticated landing system is all well and nice, but there is something to be said for slapping a couple feet of armour plating on it, dropping it from orbit and letting it create a crater…saves all this time that we had planned for digging
April 9th, 2008 at 7:45 am
And yes, I have a feeling Ive been corrupted by many space age novels where humans strictly strap guns to giant hulking pieces of metal